铋基半导体复合光催化剂的制备及可见光催化性能探究

发布时间：2018-03-20 18:46

本文选题：光催化　切入点：可见光　出处：《华东理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：半导体光催化技术能够利用太阳光将水中有机污染物完全降解,具有操作简单、成本低、无二次污染等优点,是一种"绿色"的环境净化技术。铋基半导体材料具有良好的光催化性能,但较窄的可见光吸收范围和较低的量子利用率极大地限制了其实际应用。本论文通过半导体复合的手段对铋基材料进行改性,以增强对染料污染物的吸附能力、拓宽光响应范围及加快光生电子-空穴对的分离速率,从而提高其可见光降解有机污染物的活性和稳定性。本论文主要研究内容如下:在不加入有机表面配体的条件下,采用溶剂热和沉积-原位光还原法合成纳米片状结构Ag/AgCl/Bi2OCO3等离子体光催化剂。相比于Ag/AgCl和Bi2O2CO3,Ag/AgCl/Bi2O2CO3对罗丹明B(RhB)和亚甲基蓝(MB)的吸附能力和可见光催化效率明显提高。当Ag/AgCl负载量为20 wt%时,此催化剂对RhB展现出较高的可见光催化活性和稳定性,同时也表现出良好的可见光降解苯酚性能。Ag纳米粒子表面等离子体共振效应及Ag/AgCl和Bi2O2CO3的协同作用使20 wt%Ag/AgCl/Bi2O2CO3拥有优异的光催化性能。通过温和的溶剂热法制备分层微球结构的Bi2Mo06,并在此基础上合成了 Z型Ag/AgBr/Bi2MoO6光催化剂。在可见光照射下Ag/AgBr/Bi2MoO6对RhB呈现出较优的光催化效率(0.180min-1),明显高于 Ag/AgBr(0.071 min-1)和 Bi2MoO6(0.008 min-1),且具有良好的稳定性。同时,Ag/AgBr/Bi2MoO6对MB和苯酚都表现出高的可见光降解活性,说明该材料是一种广普高效的可见光光催化剂。该催化剂光催化活性的增强归因于AgBr和Bi2MoO6合适的能带位置以及体系中的Ag纳米粒子作为电子传输介质而构建的Z型光催化反应体系。
[Abstract]:Semiconductor photocatalytic technology can completely degrade organic pollutants in water by using solar light, which has the advantages of simple operation, low cost, no secondary pollution and so on. Bismuth based semiconductor materials have good photocatalytic properties. However, narrow visible light absorption range and low quantum utilization rate greatly limit its practical application. In this paper, bismuth based materials are modified by semiconductor recombination to enhance the adsorption capacity of dye pollutants. In order to improve the activity and stability of photodegradation of organic pollutants by broadening the photoresponse range and accelerating the separation rate of photogenerated electron-hole pairs, the main contents of this thesis are as follows: without the addition of organic surface ligands, Nano-flake Ag/AgCl/Bi2OCO3 plasma photocatalysts were synthesized by solvothermal and in situ photoreduction. Compared with Ag/AgCl and Bi2O2CO3 AgClP / Bi2O2CO3, the adsorption capacity and visible photocatalytic efficiency of Rhodamine Bhl / Bi2O2CO3 for Rhodamine (RhB) and methylene blue (MBB) were significantly improved when Ag/AgCl was used. When the load is 20 wt%, The catalyst exhibited high visible light activity and stability for RhB. The surface plasmon resonance (SPR) effect of Ag nanoparticles and the synergistic effect of Ag/AgCl and Bi2O2CO3 made 20 wt%Ag/AgCl/Bi2O2CO3 have excellent photocatalytic performance. The layered microparticles were prepared by mild solvothermal method. Bi2Mo06. on the basis of this, Z type Ag/AgBr/Bi2MoO6 photocatalyst was synthesized. The photocatalytic efficiency of Ag/AgBr/Bi2MoO6 to RhB under visible light irradiation is 0.180min-1, which is obviously higher than that of Ag/AgBr(0.071 min-1) and Bi2MoO6(0.008 min-1n, and it has good stability. At the same time, Ag/AgBr/Bi2MoO6 / AgBr-Bi2MoO6 pairs have good stability. MB and phenol both showed high visible light degradation activity. The results show that this material is a widely used and efficient visible photocatalyst. The enhancement of photocatalytic activity of the catalyst is attributed to the appropriate band positions of AgBr and Bi2MoO6 and the Z formed by Ag nanoparticles in the system as electron transport media. Type A photocatalytic reaction system.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36

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